Ouachita Parish, Louisiana

Ouachita Parish, Louisiana
Ouachita Parish Courthouse in Monroe was built in the 1930s by the contractor George A. Caldwell
Location within the U.S. state of Louisiana
Louisiana's location within the U.S.
Country United States
State Louisiana
RegionNorth Louisiana
FoundedMarch 31, 1807
Named afterOuachita people
Parish seat (and largest city)Monroe
Area
 • Total
632 sq mi (1,640 km2)
 • Land610 sq mi (1,600 km2)
 • Water21 sq mi (54 km2)
 • percentage3.4 sq mi (8.8 km2)
Population
 (2020)
 • Total
160,368
 • RankLA: 8th
 • Density260/sq mi (100/km2)
Time zoneUTC-6 (CST)
 • Summer (DST)UTC-5 (CDT)
Area code318
Congressional district5th
WebsiteOuachita Parish Police Jury

Ouachita Parish is a parish located in the northern part of the U.S. state of Louisiana. As of the 2020 census, the population was 160,368. The parish seat and largest city is Monroe. The parish was formed in 1807.

Ouachita Parish is part of the Monroe, Louisiana Metropolitan Statistical Area. Located here is Watson Brake, the oldest indigenous earthwork mound complex in North America. It was built around 3500 BC, making it older than the Ancient Egyptian pyramids or Britain's Stonehenge. It is on privately owned land and not available for public viewing.